Flotation of minerals.



UNITED sTATEs PATnnToFFIo HARRY P. COBLISS, F PITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 METALS RECOVERY COMPANY, OENEW YORK, N. Y., A. CORPORATION OF MAINE. I

FLOTA'IION or mmnnans.

Be it known that I, HARRT P. OoRLIss, citizen of the United States, residin Pittsburgh,jcounty of Allegheny, and. tate" of Pennsylvania, have invented certain new and useful Improvements in the Flotation of Minerals; and I do hereby declare the following to be a full, clear, and exact description of the invention such as will enable others, skilled 'in the artto which it appertains to make and use the same I This invention relates to the concentration ofmineral's, such as sulfid ores and the like, by. flotation and is based upon'the discovery thatimproved results can be obtained bycafrrying out the flotation operation'with the addition to the ore or mineral pulp of alpha-naphthylamin either alone, or with added amounts of oil. The alpha-naphthylamin is a non -oleaginous solid material which can [nevertheless be distributed throughout the ore pulp with such uniformity that minimum amounts are required for effecting the concentration of the mineral by flotation. It"isnot necessary that chemically'pure na' hthylamin be used, but the commercial pro not (made, for example,

by reducing nitro-naphthalene) can beused in its crude-or unrefined state, the reduction eflected for example by means of iron fk and' hydrochloric acid.- The product thus produced is found to be substantially as efificient a S'a product. of higher purity.

In using the alpha-naphthylamin it may be added to the ore, either alone or with addedamounts 'of oil, in any suitable manner, so that it will be thoroughly and uniformly distributed throughout the ore pulp.

Y The mixture is then subjected to a flotation operation as'in. an ordinary Callow cell or in apparatus where the air is incorporated in the ore pulp by mechanical agitation.

With some ore pulps it may be desirable to add either small amounts of acids or of alkalis, depending u on the nature of the orepulp to be treated The amount of alpha-naphthylamin used mayvary somewhat, for example, between Specification of Letters Patent.

Application filed March 21, 1917'. Serial No. 15e,4 1.

one-half pound and one'and one-half pounds per ton of ore (that is, ,calculated'on the welght of the ore and not of the ore pulp).

The results obtained by carrying on the flotation with the addition ofalpha-naphthylamin or with alpha-naphthylaminand added oil, indicate that higher grades of concentratesand better recoveries can be-obtained than with the usual oil mixtures and Patented May 29,- 1917.;

even withmost, if not all, of the..'best. oilmixtures. I

It is a further characteristic of the invention that the froth obtained is readily broken up and-the alpha-naphthylamin recovered therefrom, so that itls available for use in the treatment of further amounts of ore. That is to say, the circuit water recovered from the concentrate and even that recovered from the tailings contains notable amounts of alpha-naphthylaminwhich can thus be returned to the process with resulting economy in the amount required to be added for subsequent operations.

In applying the alpha-naphthylamin it may be introduced into the tube mill in which the ore is being ground or it may be otherwise introduced into the ore pulp in any suitable Way, as, for instance, by first digesting it in hotwater and mixing the product with the ore pulp just before it kenters th flotation cell.

H Having thus described my invention, what I claim is:

1. The method of eflecting the concentration of minerals by flotation, which comprises adding to the mineral pulp a small amount of alpha-naphthylamin andsubjecting the resulting mixture to a flotation operation; substantially as described.

2. The method of effecting the concentration of minerals by flotation, which comprises adding to the mineral pulp a small amount of alpha-naphthylamin and of oil and subjecting the resulting mixture to a flotation operation;' substantially as described.

HARRY P. CORLISS.

In testimony whereof aflix my signature. 

